CHEM 60 Spring 2016 Exam 1 Ch 1-4, 100 points total.

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1 Name Exam No. A CHEM 60 Spring 2016 Exam 1 Ch 1-4, 100 points total. Multiple Choice. (20 questions, 3 points each = 60 points total) Mark the letter on the scantron form corresponding to the one best answer for each question or problem. Be sure to write your name on your scantron and align the question number with the answer bubble. No partial credit will be given. You may use any space within the multiple choice section as your scratch paper, if you need extra scratch paper, use the back of any page. 1) Convert to standard scientific notation. A) B) C) D) ) The definition of a scientific law is: A) the same as a hypothesis. B) a way of learning that emphasizes observation and experimentation. C) the underlying reason for a scientific theory. D) a number of similar observations generalized into a brief statement summarizing past observations and predicting new ones. 3) How many significant figures are there in the answer for the following problem? [( ) 1.05] =? A) one B) two C) three D) four 4) Read the length of the metal bar with the correct number of significant figures. A) cm B) 15 cm C) 20 cm D) cm E) 15.0 cm 5) How many kilojoules are there in 95.0 Calories? A) B) 397 C) 22.7 D) E) ) How many in 3 are in 2.20 cm 3? A) B) 7.45 C) 10.6 D) 36.1 E) 134 7) Strontium belongs to the group of the periodic table. A) halogen B) alkaline earth C) noble gas D) alkali metal 8) What is the charge on the ion formed by selenium? A) 2+ B) 1- C) 2- D) 1+ E) 0 1

2 9) Which of the following statements about the nature of electrical charge is FALSE? A) Positive and negative electrical charges attract each other. B) Electrical charge is a fundamental property of protons and electrons. C) Positive-positive or negative-negative charges repel each other. D) Positive and negative charges cancel each other so that a proton and electron, when paired, are charge neutral. E) All of the above statements are true. 10) The jet fuel in an airplane has a mass of 97.5 kg and a density of g/cm 3. What is the volume of this jet fuel? A) cm 3 B) cm 3 C) cm 3 D) cm 3 11) A popular science demonstration is to take several liquids that will not mix together and "stack" these liquids in a tall glass cylinder. Suppose the following three liquids were placed in the same tall, narrow glass cylinder: SUBSTANCE DENSITY g/ml vinegar 1.01 motor oil 0.87 corn syrup 1.36 These liquids would stack in which order? A) vinegar on top, motor oil in the middle, corn syrup on the bottom B) motor oil on top, corn syrup in the middle, vinegar on the bottom C) corn syrup on top, vinegar in the middle, motor oil on the bottom D) corn syrup on top, motor oil in the middle, vinegar on the bottom E) motor oil on top, vinegar in the middle, corn syrup on the bottom 12) Which of the following is NOT part of Dalton's Atomic Theory? A) Atoms combine in simple, whole-number ratios to form compounds. B) Each element is composed of tiny indestructible particles called atoms. C) All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements. D) Most of the atom's mass and all of its positive charge is contained in a small core called the nucleus. E) All of the above are part of the atomic theory. 13) Given the table of specific heat values below, what is the identity of a 10.0 g metal sample that increases by 14.0 C when 62.9 J of energy is absorbed? A) Au B) Al C) Ag D) Fe E) Pb 14) What is the final temperature of 25.0 grams of water at 22.0 C after it absorbs 454 J of heat? A) 17.7 B) 26.3 C) 15.8 D) 4.29 E)

3 15) A fictional element has two naturally occurring isotopes with the natural abundances shown here: ABUNDANC ISOTOPE E % % Which statement is TRUE for this element? A) The atomic mass would be greater than 20. B) The atomic mass would be exactly 19. C) The atomic mass would be closer to 20 than to 18. D) The atomic mass would be less than 18. E) The atomic mass would be closer to 18 than to ) Group 1A elements are also called: A) noble gases. B) halogens. C) alkaline earth metals. D) alkali metals. 17) Which among the following statements is FALSE? A) A gas has neither definite volume nor definite shape. B) Both solids and liquids are incompressible while gases are compressible. C) A solid has a definite shape and a definite volume. D) A liquid has a definite volume; but it has no definite shape. 18) Which of the following items is a mixture? A) brass B) helium C) sugar D) water E) silver 19) A solution is an example of a (an): A) pure substance. B) element. C) heterogeneous mixture. D) compound. E) homogeneous mixture. 20) All of the following can be considered physical properties EXCEPT: A) density. B) flammability. C) boiling point. D) color. E) taste. 3

4 In the space provided below each problem, show a neat, complete, and logical method for solving the problem. You must show the appropriate unit on each number throughout the set-up. Place your answer in the space provided with the correct number of significant figures and units wherever necessary. Use the back of these pages if you run out of room or if you need more paper. 1) Write the correct name or symbol for the following: (1 point each, 10 total, no partial credit, spelling counts) Mn silver Rb lead At copper Sb radon Ge niobium 2) Fill in the blank spaces below. (0.5 point each box, 5 total) Element Symbol (Show A and Z ) Mass No. No. of protons No. of electrons No. of neutrons Br Zn 2+ 3) A 155-lb patient is to undergo surgery and will be given an anesthetic intravenously. The safe dosage of anesthetic is 11 mg/kg of body weight. Determine the maximum dose of anesthetic (in µg) that should be used. (5 points) 4

5 4) A lead sphere measures 1.50 in in diamter. What is the mass (in kg) of this sphere? (5 points) 5) Silicon has three naturally occurring isotopes: Si-28, Si-29, and Si-30. Si-28 with a mass of amu and a natural abundance 92.21%, the rest is Si-29 and Si-30. Si-29 has a mass of amu and Si-30 has a mass of amu. Determine the relative abundance of Si-29 and Si-30. Be sure to tell me which relative abundance is for which isotope. (5 points) 5

6 6) In an experiment, a 15.0 g of an unknown metal is heated to 80.0 C and plunged into an insulated container containing 50.0 g of water initially at 25.0 C. The metal and water are allowed to come to thermal equilibrium and the final temperature is 30.0 C. a. Calculate the specific heat capacity of the metal. (5 points) b. If the unknown metal is made of iron, calculate the % error for this experiment. (3 point) c. State only two potential sources of errors for this experiment and state what you can do to improve the results of this experiment. (2 points) 6